X100S vs D7100 (or a comparable slr)

I've recently entered the wonderfully daunting world of photography and learnt how to use a camera and get nice shots on a g15 compact. I want to upgrade to a higher end system, so I sold the g15, thinking I'd jump right on the mirrorless-fuji-X100S bandwagon, but now I'm conflicted. I mainly love doing street photography, as well as some portraits, and I torn between the fuji and going with cheaper dslr with no aa filter, then popping a nice lens on it, like the sigma 30 1.4 art or whatever they're calling it.